Historically, the exchange of documents between two or several persons was achieved in three ways: physically, virtually and transitory (whereas the document is transmitted partly physically and partly virtually). The documents existed in two formats, the paper document and the virtual format (such as computer files).
When two or more persons exchanged virtual documents physically, it was done by transferring information using a USB device, a CD or other media physical media containing virtual documents. The exchange then involved a physical device that was transferred from one person to another.
More recently, computer systems and networks have facilitated the exchange of virtual documents using devices such as computers, smart phones, or iOS™ products. The exchange of information may also be accomplished by email, with the possibility of attaching files or use of other FTP services. Such transfers are virtual exchanges.
A transitory exchange is a combination of the virtual and physical formats. One example is the use of a fax for the transfer of information. Information in the virtual form is delivered (the electronic file) in a physical form (the sheet of paper) by the fax.